Not Applicable
The present invention relates to cutters used for slitting non-metallic sheathed cables.
Preparation of electrical cables for attachment to various connectors is a routine practice in the electrical trades. Cable preparation entails a number of operations. For example, when preparing a non-metallic sheathed cable, the cable must first be cut to a desired length. After the cable is cut to the desired length, the sheathing near the end of the cable must be slit to expose insulated electrical conductors within the cable, and the slit portion of the sheathing must be cut off. Subsequently, short lengths of insulation must be removed from the ends of the insulated conductors to expose the electrical conductors. Following the removal of the insulation at the ends of the insulated conductors, the electrical conductors are prepared for attachment via screw connections. Each electrical conductor is typically formed into a loop that is wrapped around a screw, and the screw is tightened to form a secure electrical connection. Because of the repetitive nature of the above-described tasks in the electrical trade, it is desirable to perform these tasks in a straightforward and efficient manner.
The most common tool employed in the electrical trades for the preparation of non-metallic sheathed cables is the wire stripper tool, which is available commercially from numerous vendors. One commercially available wire stripper tool is depicted in FIG. 1. While wire stripper tools differ in various minor aspects, each typically includes a pair of handles connected to offset jaw portions. The handles are pivotally attached so that squeezing the handles causes the jaw portions to close. One section of each jaw portion includes a blade for cutting non-metallic sheathed cables including insulated electrical conductors. Another section of the jaw portion is adapted for severing and removing insulation from various gauge insulated conductors. A third section of the jaw portion near the tips of the respective jaw portions is adapted for grabbing the conductors when the handles are squeezed together. As noted in FIG. 1, the commercially available wire stripper tool includes a hole that extends through at least one of the jaw portions. Once the insulation has been removed from the end of an insulated conductor, the exposed electrical conductor may be inserted through the hole in the jaw portion of the wire stripper tool and bent to form a loop at the end.
Existing wire stripper tools do not include any apparatus for slitting non-metallic sheathed cables. Accordingly, tradesman and others involved in cable preparation normally use another tool for this purpose. For example, a jack knife or a utility knife may be employed to slit a non-metallic sheathed cable. Additionally, the sheathing slitter and cutter tool disclosed in U.S. Pat. No. 6,247,235 that is owned by the owner of the present application may be used to slit a non-metallic sheathed cable. Because these tools are separate from the wire stripper tool, they may be misplaced. Moreover, because a separate tool is employed for slitting the sheathed cable, the operation is not as efficient as desired.
A cable sheathing slitter attachment for a wire stripper tool is disclosed. In one embodiment the cable sheathing slitter attachment includes a blade member and a guard member that may be mounted to a wire stripper tool via use of a fastener. The blade member includes a mounting portion having at least one opening that is located so as to align with a hole in a jaw portion of the wire stripper tool when the blade member is disposed in a mounting position relative to the wire stripper tool. Additionally, the blade member includes a blade portion that is integrally formed with the mounting portion and that extends from the mounting portion of the blade member. The blade portion includes first and second knife edges, the first knife edge being oriented so as to face the front end of the wire stripper tool and the second knife edge being oriented so as to face the rear end of the wire stripper tool.
The guard member includes a mounting portion and a U-shaped blade guard portion that is integral with the mounting portion of the guard member. An opening is provided in the mounting portion of the guard member to permit pivotal mounting of the guard member with respect to the blade member. A fastener, such as a shoulder bolt is inserted through the opening in the mounting portion of the guard member, through the opening in the blade member and through the hole in the jaw portion of the wire stripper tool. A nut is threaded onto the bolt and tightened to secure the blade member in position with respect to the respective jaw of the wire stripper tool while allowing the guard member to pivot around the fastener with respect to the blade member. The first knife edge that faces the forward end of the wire stripper tool may be used for slitting non-metallic sheathed cable by urging the first knife edge forward and into the cable sheathing. The second knife edge that faces the rear end wire stripper tool may be used for slitting non-metallic sheathed cable by urging the tip of the second knife edge into the cable and pulling the wire stripper tool to slit the cable. The first and second knife-edges may be employed to slit the sheathing of non-metallic sheathed cables of virtually any size. The guard member is pivotally mounted with respect to the blade member and may be rotated into a first position in which the U-shaped portion of the guard member covers the knife-edges of the blade portion of blade member when the cable sheathing slitter attachment is not being used. When it is desired to slit non-metallic sheathed cables, the guard member may be pivotally rotated around the fastener into a second position in which the guard is clear of the knife edges.
In another embodiment of the invention, a blade member is pivotally mounted to or within a jaw of a wire stripper tool. In the second embodiment, the wire stripper tool is configured to provide a guard that is integrally formed as a part of a jaw of the wire stripper tool. The blade member may be rotated into a first position in which the knife-edges on the blade portion of the blade member are exposed for use. Additionally, the blade member may be rotated into a second position in which the knife-edges are oriented with respect to the jaw so as to prevent inadvertent contact with the knife-edges of the blade member.
Other features, aspects, and advantages of the present invention will be apparent from the Detailed Description of the Invention in conjunction with the drawing.